Earth Planets and Space · 2006 · 79 citations · 31 references
Natural SciencesEarth SciencesGeophysicsEarthquake PhysicsGeodesySeismologyEarthquake Ground MotionEarthquake Source ProcessesIonospheric ElectrodynamicsSeismic Wave PropagationIonospheric DisturbancesIonospheric Total Electron ContentSudden Ionospheric DisturbancesTotal Electron Content VariationsTraveling Ionospheric Disturbances
Abstract By using data from the GPS network, we observed exceptional intensive quasi-periodical perturbations of the total electron content (TEC) caused by the great Sumatra-Andaman earthquake on 26 December 2004. The time period of the variations was about 15 min, their duration was about 1 hour. The amplitude of the TEC oscillations exceeded the amplitude of “background” fluctuations in this range of periods by one order of magnitude, at a minimum. They were registered 2–7 hours after the main shock at a distance from 1000 to 5000 km, both on the northwest and northeast outward from the epicenter. The most probable source of the observed oscillations appeared to be a seismic airwave generated by the sudden vertical displacement of the Earth’s surface near the epicenter.
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